This invention relates to a wire harness for an automotive vehicle, in which a plurality of insulator-sheathed electric wire elements are juxtaposed on a plane and are provided at suitable positions with connectors, and relates to a method and an apparatus for producing the wire harness.
Electrical appliances in an automotive vehicle are electrically interconnected through wire harnesses. For convenience of explanation a typical example of the conventional wire harnesses is described below by referring to FIGS. 11 to 13B. FIG. 11 is an explanatory view of a conventional wire harness. FIG. 12 is a perspective view of a conventional plat electric wire. FIGS. 13A and 13B are explanatory views of a conventional method for branching the wire harness.
A typical conventional wire harness, as shown in FIG. 11, has a plurality of insulator-sheathed electric wire elements a and connectors c attached to the wire elements a. However, a work of inserting every wire element a into the connector individually is troublesome and raises a cost of the wire harness.
Consequently, a so-called flat electric wire P shown in FIG. 12 has been utilized. Since this wire P is made of a plurality of single core electric wire elements a juxtaposed integrally, the elements a are not separated from each other and thus the wire is easy to handle. Further, this wire is useful since insulator displacement terminals can be connected to the wire elements at a time (see FIGS. 13, 2A, and 2B).
However, the electric wire P, as shown in FIG. 12, has an integrated insulator sheath for each wire element a and thus is very expensive in comparison with the same number of single core insulator-sheathed electric wire elements a. It is desirable to produce the electric wire P (wire elements a) as inexpensively as possible since the wire harnesses are used in so many circuits.
In the event that the wire harness W is arranged, for example, from a joint box B to each electric appliance D, as shown in FIG. 11, the number of the wire elements a is decreased as they are away from the joint box B. When such wire harness W shown in FIG. 11 is formed by using the flat electric wire P shown in FIG. 12, insulation displacement terminals t shown in FIGS. 13A and 13B are usually utilized to connect each wire element a to the connector C. At this time, the wire element axe2x80x2 (FIG. 13A) which extends over a branch becomes useless. Although such useless wire element axe2x80x2 should be removed from the wire harness in view of a cost, the removement process of the insulator-integrally-sheathed electric wire P will raise a cost.
Also, positions of the insulation displacement terminals t at the respective branching portions are not adjacent to each other but at random, as shown in FIGS. 13A and 13B. The positions of connector terminals in the joint box are different from those of the terminals in the branching connector C on account of the respective electric appliances of different makers. Thus, it will be understood from the drawings that distances between the terminals t to be simultaneously brought into insulation displacement contact are different and an insulation displacement work for the terminals are complicated. If the distances between the terminals are constant, the work will be simplified. If the distances between the terminals are different, there may be necessary wire elements a between the wire elements a to be cut and thus this results in a difficult work of removing the useless wire element axe2x80x2.
An object of the present invention is to lower a producing cost of a wire harness for an automotive vehicle.
Another object of the present invention is to provide a method for producing a wire harness for an automotive vehicle, in which a cost can be lowered.
Still another object of the present invention is to provide an apparatus for producing a wire harness for an automotive vehicle, in which a cost can be lowered.
In order to achieve the above objects, a wire harness for an automotive vehicle in accordance with the present invention includes a plurality of insulator-sheathed electric wire elements juxtaposed on a plane, the given electric wire elements being secured together to a connector by an insulation displacement manner at the given their positions in the length and width directions.
Since the wire harness of the present invention is formed by together pressing the plural electric wire elements directly on the connector, the wire harness becomes simpler in construction and lower in cost than a conventional wire harness. It is possible to utilize an insulator-sheathed electric wire element having a minimum diameter, for example, 1 mm or less and also to use the elements with different diameters.
The insulator-sheathed electric wire elements are juxtaposed on a plane at the same pitch as that of terminals in the connector and in the event that the electric wire elements have different lengths and the electric wire elements to be secured to the connector are reduced the given electric wire elements are gathered in the width direction at the same pitch and then secured together to the connector by the insulation displacement manner.
It is possible to use a connector having terminals corresponding to the reduced wire elements, thereby making a connector compact and cheap.
A third connector is disposed between first and second connectors and given electric wire elements secured to the first, second and third connectors have a length longer than that of the other electric wire elements secured to the first and second connectors.
A connector on which a part of the electric wire elements is pressed does not project from the other electric wire circuit, thereby increasing a flexibility of connection to each electric appliance.
A method for producing a wire harness for an automotive vehicle in accordance with the present invention comprises the steps of:
juxtaposing a plurality of insulator-sheathed electric wire elements on a plane;
passing the juxtaposed wire elements through a gripper and a cutter;
clamping ends of the juxtaposed wire elements by a chuck of a measuring and drawing device;
advancing the chuck until the juxtaposed wire elements are disposed in an insulation displacement press device;
securing given wire elements of the juxtaposed wire elements to a connector in an insulation displacement manner by the press device;
drawing the other juxtaposed wire element by a desired length from the press device by advancing the chuck;
securing given wire elements of the other juxtaposed wire elements to the connector in an insulation displacement manner by the press device;
attaching given wire elements of the juxtaposed wire elements to the connector at desired positions in length and width directions of the wires by repeating the above steps;
cutting off given wire elements of the juxtaposed wire elements behind the connector by the cutter in accordance with a working requirement; and
cutting off opposite ends of all of the juxtaposed wire elements to form a wire harness.
The above third through fifth steps may be replaced by the steps of: disposing ends of the juxtaposed wire elements in an insulation displacement press device; securing the ends of given wire elements of the juxtaposed wire elements to a connector in an insulation displacement manner by the press device; and clamping the other ends of the juxtaposed wire elements by a chuck of a measuring and drawing device.
The wire elements after being cut may be gathered in the width direction to accord with a pitch between terminals juxtaposed in the connector. The wire elements are secured to the connector in an insulation displacement manner.
In the step of attaching the wire elements to the connector a group of wire out of the juxtaposed wire elements are drawn from the gripper by a length longer than that of the other wire elements and then the group of wire elements are secured to the connector in an insulation displacement manner.
An apparatus for producing a wire harness for an automotive vehicle in accordance with the present invention, comprises: a gripper, a cutter, an insulation displacement press device, and a measuring and drawing device which are arranged on straight line in order and through which a plurality of insulator-sheathed electric wire elements juxtaposed on a plane pass. The measuring and drawing device is adapted to clamp ends of the juxtaposed wire elements and draw the wire elements by a desired length by a chuck provided in the device. The insulation displacement press device is adapted to secure the wire elements to a connector in an insulation displacement manner. The cutter is adapted to cut off any wire element out of the juxtaposed wire elements. The gripper is adapted to clamp ends of the juxtaposed wire elements after all of the wire element are cut off and to displace the ends to the chuck of the measuring and drawing device.
A wire-gathering device may be provided on the rear side of the cutter, and wherein the wire-gathering device is adapted to gather the juxtaposed wire elements in the width direction to accord with a pitch between terminals juxtaposed in the connector.
A wire-drawing device maybe provided on the rear side of the insulation displacement press device. The wire-drawing device is adapted to clamp a group of the juxtaposed wire elements and to draw the group of wire elements by a desired length from the gripper.